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排序方式: 共有101条查询结果,搜索用时 46 毫秒
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Ameer Fawad Zahoor Muhammad Yousaf Rabia Siddique Sajjad Ahmad Syed Ali Raza Naqvi Sayyad Muhammad Ali Rizvi 《合成通讯》2017,47(11):1021-1039
Enoxacin, levofloxacin, and gatifloxacin represent one of the most important prerogative scaffolds in drug development. They possess broad spectrum antimicrobial and anti-inflammatory activities. They inhibit bacterial growth by blocking their topoisomerase enzyme which is necessary for the proper functioning of bacterial DNA. In this article, we have reviewed the synthetic approaches involved in the synthesis of derivatives of enoxacin, levofloxacin, and gatifloxacin. 相似文献
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ABSTRACTProfessor Graham Higman has defined coset diagrams for the action of PGL(2,?) on the projective line over a finite field Fq, denoted by PL(Fq), where q is a prime power. These diagrams are composed of circuits. In this paper, we answer the question, for a fixed number of triangles T, how many distinct circuits of length 4, are evolved? 相似文献
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M. Nur‐e‐Alam Muhummed Yousaf Samina Qureshi Irfan Baig Shama Nasim Atta‐ur‐Rahman M.Iqbal Choudhary 《Helvetica chimica acta》2003,86(3):607-614
A novel dimeric lignan, bispicropodophyllin glucoside ( 1 ) and a highly oxygenated new withanolide, coagulin S ( 2 ) were isolated from the ethanolic extract of Withania coagulans. The structures were established on the basis of the spectroscopic data and have been identified as (5S*,5aR*,8aR*,9S*,15S*,15aS*,18aS*,19S*)‐9,19‐di‐β‐D ‐glucopyranosyl‐5,8a,9,15,15a,18,18a,19‐octahydro‐5,15‐bis(3,4,5‐trimethoxyphenyl)bis([1,3]dioxolo[4′,5′:6,7]naphtho)[2,3‐c:2,3‐h][1,6]dioxecin‐6,16(5aH,8H)‐dione ( 1 ) and (20S*,22R*)‐5α,6β,14α,15α,17β,20,27‐heptahydroxy‐1‐oxowith‐24‐enolide ( 2 ), respectively. 相似文献
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Luo W Westcott NP Pulsipher A Yousaf MN 《Langmuir : the ACS journal of surfaces and colloids》2008,24(22):13096-13101
In this report, we show the successful transfer of a sophisticated electroactive immobilization and release strategy to an indium tin oxide (ITO) surface to generate (1) optically transparent, robust, and renewable surfaces, (2) inert surfaces that resist nonspecific protein adsorption and cell attachment, and (3) tailored biospecific surfaces for live-cell high-resolution fluorescence microscopy of cell culture. By comparing the surface chemistry properties on both ITO and gold surfaces, we demonstrate the ITO surfaces are superior to gold as a renewable surface, in robustness (durability), and as an optically transparent material for live-cell fluorescence microscopy studies of cell behavior. These advantages will make ITO surfaces a desired platform for numerous biosensor and microarray applications and as model substrates for various cell biological studies. 相似文献
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Hamza Bayad Ahmed El Manouni Bernabé Marí Yousaf H. Khattak Shafi Ullah Faisal Baig 《Optical and Quantum Electronics》2018,50(6):259
In order to improve photovoltaic performance of solar cells based on ZnTe thin films two device structures have been proposed and its photovoltaic parameters have been numerically simulated using Solar Cell Capacitance Simulator software. The first one is the ZnO/CdS/ZnTe conventional structure and the second one is the ZnO/CdS/ZnTe/P+-ZnTe structure with a P+-ZnTe layer inserted at the back surface of ZnTe active layer to produce a back surface field effect which could reduce back carrier recombination and thus increase the photovoltaic conversion efficiency of cells. The effect of ZnO, CdS and ZnTe layer thicknesses and the P+-ZnTe added layer and its thickness have been optimized for producing maximum working parameters such as: open-circuit voltage Voc, short-circuit current density Jsc, fill factor FF, photovoltaic conversion efficiency η. The solar cell with ZnTe/P+-ZnTe junction showed remarkably higher conversion efficiency over the conventional solar cell based on ZnTe layer and the conversion efficiency of the ZnO/CdS/ZnTe/P+-ZnTe solar cell was found to be dependent on ZnTe and P+-ZnTe layer thicknesses. The optimization of ZnTe, CdS and ZnTe layers and the inserting of P+-ZnTe back surface layer results in an enhancement of the energy conversion efficiency since its maximum has increased from 10% for ZnO, CdS and ZnTe layer thicknesses of 0.05, 0.08 and 2 µm, respectively to 13.37% when ZnO, CdS, ZnTe and P+-ZnTe layer thicknesses are closed to 0.03, 0.03, 0.5 and 0.1 µm, respectively. Furthermore, the highest calculated output parameters have been Jsc?=?9.35 mA/cm2, Voc?=?1.81 V, η?=?13.37% and FF?=?79.05% achieved with ZnO, CdS, ZnTe, and P+-ZnTe layer thicknesses about 0.03, 0.03, 0.5 and 0.1 µm, respectively. Finally, the spectral response in the long-wavelength region for ZnO/CdS/ZnTe solar cells has decreased at the increase of back surface recombination velocity. However, it has exhibited a red shift and showed no dependence of back surface recombination velocity for ZnO/CdS/ZnTe/P?+?-ZnTe solar cells. 相似文献
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